Improvement in steam-boilers



J. H. WILKINSON.

Steam-Boiler.

No.|67,595 Pa1en tedSept.7,l875.

N.FEIERS. PNOTO-UTHOGRAPHER, WASHINGTON n c JOSEPH H. WILKINSON, OFSOUTH NEW MARKET, NEW HAMPSHIRE.

\MPROVEMENT IN STEAM-BOILERS.

&

Specification forming part of Letters Patent No. l67,595, datedSeptember 7. 1875; application filed April 12, 1875.

To all whom it may concern:

Be it known that I, J os. H. WILKINSON, of South New Market, in thecounty of Rockingham and State of New Hampshire, have invented certaiunew and useful Improvements in Marine and other Steam Boilers; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit pertains to make and use it, reference being had to the accom iauyiugdrawings, which form part of this specification.

My invention relates, mainly, to marine boilers, but may be applied withgreat advantage to other boilers also.

The nature of my invention consists in preventing the heated products ofcombustion from leaving the boiler proper too freely, and in causing auniform How of the same through the tubes.

The annexed drawings fully illustrate my invention, and represent asingle marine boiler provided with two fires.

A A are the fire-chambers; B, the front uptake or connection; 0 G, thetubes; and D the back connection. E is the sinoke'stack, placed near theend of the front uptake or connection B, as is the usual custom.

WVhen this plan is followed it Will be seen that a large area is formedbetween the outlet of the tubes 0 and the damper in the smokestack, intowhich the heated gases can flow when the damper is closed, and thereexhaust by radiation through a surface that is not utilized for thegeneration of steam.

It will further be seen that, when the smoke.

stack is placed at the end of the uptake, the most positive action ofthe draft is on those tubes nearest to the stack or chimney, whilelittle or no heat passes through those farthest from the chimney.

'Io equalize the flow of heat through the tubes, I construct and adjustto the front tubesheet a, or the exit end, a sliding damper, G, havingholes corresponding with the tube area.

By lowering this damper more at the end nearest to the chimney E, thepower of the draft is reduced on the near tubes by the exit of the tubesbeing more effectually closed. \Vhen, however, the exit from the frontuptake or connection B is uniform-as, for instance, it would be ifapplied to -a locomotiveboilerthe damper would be lowered uniformly.

The damper G does not close or cover up the lower rows of tubes aseffectually as the upper ones, experience showing in all cases that thelower tubes do not control the flow of the heated products of bombustionto the extent that the upper ones do, so I apply my device vertically,as well as horizontally, for the purpose of equalizing this flow.

The damper does not entirely close the tubeoutlet, nor do I deem thisnecessary. If, however, this should be required, the tubes could be setfarther apart 5 or a second damper could be used over the first one thatwould accomplish this.

Another advantage of the damper is, that it does not allow the heatedproducts of combustion to flow along the upper surface of the tube, butconverts the upper surface into a reservoir for the heated gases, andforces a a more positive action of the same on the lower surface. Again,the action of the draft being on the lower part of the'tube-that part onwhich foreign matter mostly collects-this foreign matter is moreeffectually sucked out by the action of the draft.

Heated air naturally rises under all circumstances, aud the consequenceis that, as the heated products of combustion pass through the tubes,their upper portions are intensely heated, while their lower parts arenot, thus causing an unequal expansion and contraction that is veryinjurious to both tubes and boilerheads.

IVIy invention is designed to remedy this defect, and to cause all partsof the tubes to be heated equally, and especially to cause the draftthrough all the tubes to be equalized. Where the damper slides down fromabove, so as to close only the upper ends of the tubes, a portion of theheated air fills the upper part of the tubes, while the balance iscompelled to flow along the lower part, and thus heat the whole of eachtube alike. Where a damper in the shape of a perforated plate is used,that is raised from below, the damper only serves to intensify all theseevils-to heat the upper parts of the tubes to an intense degree, andleave the lower parts comparatively cool, and

to Force a still greater quantity of the hot air through the upper tubesabove the water-line.

My invention consists in sliding the perforated plate from above, so asto equalize the flow of the heat through all the tubes, and to heattheir lower portions as thoroughly as their upper parts. i

The damper may be operated by any suitable mechanical means.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In combination with the exit end of the tube-sheet of a tubularboiler, a perforated sliding plate, G, that closes over the ends of thetubes from above, so as to retain a volume of hot air in theupper partsof the tubes, and

to cause the heated products of combustion to flow along the lowerportions of the tubes, as described.

2. The sliding damper G, in combination with the exit end of thetube-sheet of a tubular boiler, the damper having its opening so as toclose the upper tubes more than the lower ones, and thus equalize theflow of heated air through all of the tubes, as specified.

In testimony that I claim the foregoing I have hereunto set my hand andseal this 29th day of March, 1875.

JOS. H. WILKINSON. [L. s.]

Witnesses:

DANIEL G. LUGE, R. S. CARROLL.

